This disclosure relates to a method of producing a catalyst material having a more uniform atomic layer of platinum atoms.
Platinum is known and used as a catalytic material in electrochemical reactions, such as an electrochemical reaction within a fuel cell to generate an electric current. The platinum may be deposited on a metal core of a noble metal, which is supported on a carbon particle. To increase mass activity of the platinum, the platinum is provided as a thin layer on the noble metal core.
One conventional manufacturing process for making such catalytic materials involves first depositing a thin layer of metal atoms of a lower reduction potential than the platinum onto noble metal core particles. Some manufacturers use an underpotential deposition process to deposit copper atoms as the lower reduction potential metal. The core particles are then mixed with a solution that contains a platinum salt. The platinum atoms in the solution spontaneously displace the copper atoms on the noble metal cores to produce a thin layer of the platinum atoms on the noble metal cores.